The popularity of digital audio and video materials has led to the availability of a number of consumer electronic platforms that assist in receiving, decoding, processing and displaying digitally encoded audiovisual content on a suitable display.
Consumer electronic platforms include personal computers (PCs), digital versatile disc players (DVD players), high-definition DVD players (HD DVD players), Blu-ray players, digital television (DTV) sets, high definition television (HDTV) sets and set-top boxes. Many types of receivers are used to receive data that may be transmitted via radio frequency (RF) transmission signals, cable television signals, satellite signals or the like.
Audio and video content may also be distributed in the form of a computer readable medium such as DVD, HD DVD, Blu-ray disc (BD), compact disc (CD) or the like. Alternately, encoded audiovisual data may also be received through a telecommunications network such as the Internet, by way of a dial-up link, fiber-optic connection, coaxial cable, digital subscriber line (DSL), or the like.
Digital signal processors (DSPs) have become increasingly popular for manipulating audio and video data. The decreasing cost of embedding DSPs into a variety of electronic devices has enabled the emergence of many devices that are capable of performing many types of data, audio and video processing tasks.
It is now common to see external modems, routers, personal computers, Blu-ray or HD DVD players and display devices, often supplied by different manufacturers, interconnected together in living rooms or home entertainment centers. Decoders such as DVD players, HD DVD players, Blu-ray disc players, set-top boxes may be interconnected directly to display devices. Common display devices include cathode ray tube (CRT) monitors, flat panel displays such as liquid crystal displays (LCDs) or digital light processing (DLP) monitors, plasma displays and other digital television sets. Common audio devices include stand-alone speakers, built-in speakers typically found in various television sets and receivers equipped to receive digital audio from S/PDIF, coaxial or optical connectors. DVD players, HD DVD players, Blu-ray disc players may form part of personal computers (PCs).
Various degrees of audio and video processing capabilities can be found these platforms. For example, a PC often includes a processor, memory, audio adapter card containing an audio DSP and a video graphics card containing a graphics processing unit (GPU). The processor, audio DSP and the GPU may decode compressed audio and video data from a Blu-ray disc loaded into an interconnected Blu-ray drive. The GPU may be able to perform some video processing such as scaling or color space conversion. In addition the GPU may assist decoding by providing a hardware acceleration blocks for demanding video decoding steps. The audio DSP may be able to perform some audio processing such as tone processing, equalization, 3D virtualization or transcoding from one audio format to another.
However, the processor may also perform most or all of the required audio and video decoding tasks in a PC, especially when no hardware acceleration is available. This may be the case, for example, in a low cost personal computer without a dedicated GPU and/or audio DSP.
A PC typically interconnects a CRT monitor by way of a standard video graphics array (VGA) cable. However, the same PC may instead be connected to sophisticated digital displays by way of a digital visual interface (DVI) cable, high definition multimedia interface (HDMI) cable or a DisplayPort compliant cable. As CRT monitors typically have limited processing capabilities, a video source device that uses a CRT monitor for display typically performs essentially all of the video processing. Similarly audio data may be provided to external speakers via L/R output and/or S/PDIF compliant interfaces.
Other types of rendering devices (e.g., a digital television set) however, may have their own video processing capabilities such as scan-rate conversion, interlacing, de-interlacing, noise reduction, scaling, color correction, contrast correction, gamma correction, sharpness enhancement, edge enhancement, and frame rate conversion. In this case, at least some processing can be performed at the display device. Audio processing tasks that may be performed at a source or a sink device include volume adjustment, speaker balancing, 3D virtualization, bass/treble control, automatic volume leveling, and sound equalization.
Unfortunately, when processing capabilities are available in multiple platforms (i.e., on both the source and sink devices), these capabilities may not always be utilized efficiently. For example, a PC connected to a digital television set may perform little or no audio and video processing which requires the digital television to perform nearly all of the audio and video processing requirements. Conversely, the PC may perform nearly all the processing tasks, without utilizing potentially superior image processing algorithms available in the display device. Clearly, such an arrangement does not take full advantage of the available processing capabilities of processors, GPUs, audio DSPs and the like that may be available in both the source (e.g. PC) and sink (e.g. DTV) devices.
Accordingly, there remains a need for methods that allow effective use of the processing capabilities of multiple interconnected platforms, such as PCs and display devices.